EL ALTO, Bolivia -- President Evo Morales seemed assured of an easy victory in a referendum on Sunday over a sweeping new Constitution aimed at empowering Bolivia's Indians. The vote capped three years of conflict-ridden efforts by Mr. Morales to overhaul a political system he had associated with centuries of indigenous subjugation.

Citing preliminary vote counts, reports on national television said about 60 percent of voters had approved the new Constitution. If that margin holds or goes higher, it would strengthen Mr. Morales's mandate, political analysts here said.

Still, regional conflict over the results may loom in the months ahead. Citing the same counts, both state and private news media said at least four departments, or provinces, in Bolivia's rebellious eastern lowlands had rejected the charter by wide margins.

Vaguely worded items among the new Constitution's 411 articles would broaden definitions of property to include communal ownership; allow Indians to mete out corporal punishment under their own legal systems; extend limited autonomy to regional prefects; and reaffirm state control over Bolivia's ample natural gas reserves.

It is up to Congress to draft regulations for many of these articles, but the legislature also is an institution in flux, with Indians guaranteed new representation in its chambers.

"With my humble vote, I am creating a little bit of hope for my children," said Ismael Pocoaca, 42, a construction worker who voted Sunday morning at the Chuquiago Marka School here in this city of slums on the windswept plain overlooking the capital, La Paz.

After the vote, Mr. Pocoaca and other Aymara Indians gathered in front of the school, where vendors sold fried-pork sandwiches and posters of Mr. Morales, a former llama herder. "We are finally recapturing our dignity," said Maria Laure, 38, a soap saleswoman who voted for the new Constitution.

But while Indians across the country celebrated the vote, the Constitution opens a new stage of uncertainty in fractious Bolivia.

Few people claim to know precisely how the laws will function under the new Constitution, in what way they will undergo substantial revision in Congress or how they will affect a nation facing a sharp economic slowdown this year.

Officials in the lowlands, where most of Bolivia's food and petroleum are produced, ridiculed the new charter. "No constitution can be implemented if it has not been approved in all of the departments," said Carlos Dabdoub, a political leader in Santa Cruz, an eastern department that rejected the Constitution.

Given the festering resistance in Santa Cruz and elsewhere, it was notable that the Constitution came to a vote. Violence over the proposed charter reached a head in September when more than a dozen peasants, mostly supporters of Mr. Morales, were killed in a clash in the Amazonian department of Pando.

Talks between Mr. Morales's supporters in Congress and the splintered opposition produced a compromise from earlier versions of the charter. One of the most polemical articles in the final draft reversed a plan to allow Mr. Morales to indefinitely run for re-election, limiting him to one five-year term if he wins a new election later this year.

But other articles reflect the influence wielded by Mr. Morales, 49, an Indian who lacks fluency in Aymara and Quechua, Bolivia's main indigenous languages. Communicating with audiences in the colonialist language, Spanish, he has nevertheless forged a political movement imbued with nationalism and has heightened ethnic awareness.

"After 500 years, we have retaken the Plaza Murillo!" Mr. Morales told followers last week in a speech at the end of the campaign in La Paz's central square, which until the 1950s Indians were prohibited from entering.

The new Constitution would allow Mr. Morales, whose government is supported financially by Venezuela, to assert even greater state control of the economy, with articles that could forbid foreign companies from repatriating profits or resorting to international arbitration to resolve nationalization disputes.

Indeed, Mr. Morales seems undaunted by a dearth of investment and a slowing economy as prices decline for Bolivia's natural gas and neighboring Brazil lowers imports of the fuel.

On the eve of the vote, he announced the nationalization of a Bolivian unit of the British oil giant BP, and created a new daily newspaper, Cambio, controlled by his government. And after his recent expulsion of the American ambassador and Drug Enforcement Administration agents, whom he accuses of espionage, he repeated his criticism of the United States.

"Bolivia, little by little, is shutting itself off from the world," said Gonzalo Chávez, a Harvard-educated economist at the Catholic University of La Paz, who sees economic growth falling to 2 percent this year from about 6 percent in 2008.

But others say the new Constitution addresses underrepresentation of Indians, pointing to articles that would reserve seats for them in Congress and in other areas of the fast-growing bureaucracy. Even Mr. Morales's cabinet has just two Indian ministers; his top aides, the vice president (a former guerrilla) and the chief of staff (a former military officer), are light-skinned intellectuals.

In symbolic importance, said Xavier Albó, a Jesuit scholar and linguist, the new Constitution may be the equivalent of Spain's Reconquest of the Iberian Peninsula from the Moors in 1492. But instead of the blood spilled in that process, Mr. Albó said, Bolivia is "advancing in a democratic process that does not exclude or subjugate anyone."

Some Bolivians who read the entire Constitution came away with other impressions.

Edmundo Paz Soldán, a writer who teaches at Cornell University, said it reminded him of an essay by Jorge Luis Borges that describes a Chinese encyclopedia's attempt to divide fauna into myriad nonsensical categories. For instance, Mr. Paz Soldán said that the Constitution recognized 36 different indigenous groups in Bolivia, some with fewer than 100 people, but that it was unclear how precisely each group would be enfranchised in a country where three main indigenous groups -- the Quechua, Aymara and Guaraní -- wield much larger influence.

"The mind-boggling text may have the ratification of the majority," Mr. Paz Soldán said, "but it might not be the recipe for a viable country."